On Wed, Oct 31, 2007 at 09:27:48 -0700, Jeff Squyres wrote: > I think you should use the MPI_PROC_NULL constant itself, not a hard- > coded value of -1.
the value -1 was in the neighbor specification file. > > Specifically: the value of MPI_PROC_NULL is not set in the MPI > standard -- so implementations are free to choose whatever value they > want. In Open MPI, MPI_PROC_NULL is -2. So using -1 is an illegal > destination, and you therefore get the error that you described. now I make a check if the neighbor is -1 - then set to MPI_PROC_NULL - and voila everything is OK. > > In a different thread I read about a performance penalty in OpenMPI if more than one MPI-process is running on one processor/core - is that correct? I mean having max-slots>4 on a quad-core machine. Karsten -- ---------------------------------------------------------------------- Karsten Bolding Bolding & Burchard Hydrodynamics Strandgyden 25 Phone: +45 64422058 DK-5466 Asperup Fax: +45 64422068 Denmark Email: kars...@bolding-burchard.com http://www.findvej.dk/Strandgyden25,5466,11,3 ----------------------------------------------------------------------
